Float Bowl Drain Thread Size for tubing adapters??

[Katarat]

Thats the one I have, its the same guy that makes the o-ringed fuel tubes for the CV carbs. He sells to Z1E and on Egay

[GSOH]

I'm looking to make a set of these and it looks like there are a few different methods in this thread. I'm looking at the M5 water nipples on ebay. Seems like I could get them ($4 shipped), a set of -o-rings (if even required) and cheap clear poly tubing at local hardware. Amirite?

Not sure if the sizes are all the same; I have 82 GS850L I'm liking to make these to test. Add it to the tool bag.

M5 (M6 in different auction for same price)

http://www.ebay.com/itm/M5-threaded-water-nipples-for-rc-boat-5pcs-/130373387030?pt=US_Radio_Control_Control_Line&hash=item1e5adc0316